Good news.
I compiled a test image of Ubuntu server 20171201 with the latest version of the kernel 4.x and mainline u-boot (the file u-boot collected @numbqq).
The necessary patches to build u-boot provided by @narmstrong

At the moment in the mainline kernel has no support for USB on s905X and s912. If you really need this version, you can try a test version of the images Armbian kernel 4.14 in which the USB operates. This version of the kernel are built using a large number of patches from @narmstrong .

A test image with a Ubuntu Mate 17.04. To run on the VIM2 you need to uninstall the dtb file.img. The image uses a generic multiboot. To change the screen resolution, you need to change the script /boot/hdmi.sh (same as specified for images Armbian). The name and password of the user “khadas” , root password is “khadas”.

OK. The problem is script /etc/initramfs-tools/scripts/local-top/khadas_init.sh, maybe need to be removed if enable 0hdmi service.

No need to remove it. I deliberately made the activation of the monitor in two phases. In the first stage is a minimum value (720). In the second stage the resolution is set again with parameters needed for operation (720 or 1080). Many on TV who have no 1080 mode, it is not possible to start the system. Two stages allow to do it on any models with a direct connection and when connected via HDMI adapter-VGA.